Multi-socket connection boards and contact pins therefor

ABSTRACT

A multi-socket assembly comprises a stack of contact plates, insulating members between adjacent plates, and a plurality of electrically conductive contact rods extending perpendicularly through the stack of contact plates and interposed insulative members. Each insulating member is adapted to insulate the adjacent contact plates from each other and from the contact rods. The insulating members also define a plurality of sockets each adapted to receive a contact pin in one or another of two orientations, in order to connect a contact element to one or other of the contact rods depending on the orientation of the inserted pin. Each contact rod may be longitudinally split with the two halves insulated from one another, each half being associated with one only of the sockets flanking the rod. The contact pin comprises an electrically insulative elongate body having along one side a first contact strip; and on an opposite side is arranged a second contact strip, the contact strips being so arranged that when the pin is inserted in a socket the first contact strip engages a contact of the plate on one side of the socket and the second contact strip engages the contact rod on the opposite side of the socket. At least one of the contact strips is resilient and arranged to resist withdrawal of the pin from the socket. At least one of the pins may be longitudinally divided to provide double contacts. The first and second contact strips may be short-circuited together or electrically connected through an electrical component housed in a grip portion of the pin.

United States Patent [1 Norman Sept. 9, 1975 MULTl-SOCKET CONNECTIONBOARDS AND CONTACT PINS THEREFOR John Phillip Norman, 41 Trumpinton Rd.,Forest Gate, London E7, England 22 Filed: Mar. 8, 1913 211 Appl. No.:339,202

[76] Inventor:

[56] References Cited UNITED STATES PATENTS 296,253 4/1884 Vail 339/18 C2,449,450 9/1948 Carlson... 339/198 S X 2,905,920 9/1959 Lutton 339/173,205,469 9/1965 Frank et a] 339/252 P X 3,212,048 10/1965 Rosenberg eta1. 339/18 C 3,223,957 12/1965 Cannon r 1 339/18 C 3,345,599 10/1967Henschen et a1. 339/18 C 3,353,l38 11/1967 Loose 339/18 C PrimaryExaminerRoy D. Frazier Assistant Examiner-Terrell P. Lewis Attorney,Agent, or Firm0rrin M. Haugen [57] ABSTRACT A multi-socket assemblycomprises a stack of contact plates, insulating members between adjacentplates, and a plurality of electrically conductive contact rodsextending perpendicularly through the stack of contact plates andinterposed insulative members. Each insulating member is adapted toinsulate the adjacent contact plates from each other and from thecontact rods. The insulating members also define a plurality of socketseach adapted to receive a contact pin in one or another of twoorientations, in order to connect a contact element to one or other ofthe contact rods depending on the orientation of the inserted pin. Eachcontact rod may be longitudinally split with the two halves insulatedfrom one another, each half being associated with one only of thesockets flanking the rod. The contact pin comprises an electricallyinsulative elongate body having along one side a first contact strip;and on an opposite side is arranged a second contact strip, the contactstrips being so arranged that when the pin is inserted in a socket thefirst contact strip engages a contact of the plate on one side of thesocket and the second contact strip engages the contact rod on theopposite side of the socket. At least one of the contact strips isresilient and arranged to resist withdrawal of the pin from the socket.At least one of the pins may be longitudinally divided to provide doublecontacts. The first and second contact strips may be short-circuitedtogether or electrically connected through an electrical compo nenthoused in a grip portion of the pin.

11 Claims, 5 Drawing Figures PATENTED SEP 975 SHEET 1 OF 2 PATENTED SEP91975 saw 2 0 2 MULTI-SOCKET CONNECTION BOARDS AND CONTACT PINS THEREFORBACKGROUND OF THE INVENTION The present invention relates to amulti-socket electrical connection assembly board sometimes known as amatrix connection board, and to programme pins therefor.

ln electrical and electronic apparatus where the eiectrical connectionswithin the apparatus require to be altered from time to time, it isadvantageous to provide a matrix connection board whereby the alterationof such connections can be efiected quickly.

SUMMARY OF THE INVENTION According to the present invention, there isprovided a multi-socket assembly comprising a stack of first fixedcontact elements, insulating members between adjacent first fixedcontact elements, a plurality of second fixed contact elements eachextending perpendicularly through the stack of first fixed contactelements and inter osed insulating members, each insulating memberbetween two adjacent first fixed contact elements being adapted toinsulate them from each other and being further adapted to insulate thefirst fixed contact elements from the second fixed contact elements, theinsulating members each defining a plurality of sockets each adapted toreceive a contact pin in one or other of two orientations to areversible contact pin to connect a first fixed contact element to oneor other of two second fixed contact elements depending on theorientation of the inserted pin.

The reversible contact pin suitably comprises an in sulating basemember, a non-resilient contact member on one side of the base memberand spring-urging i contact means on the other side of the base memberwherein, on insertion of the pin into a socket, the spring-urgingcontact means comes into contact with a first fixed contact element andurges the non-resilient contact member into contact with a second fixedcontact element to effect electrical connection between the first andsecond fixed contact elements.

Each of the first fixed contact elements suitably comprises a plate witha row of contacts extending away from the plate towards the adjacentinsulating member and an aperture on either side of each contact, theseapertures forming two rows extending parallel to the rows of contacts,and the second fixed contact elements extending through the alignedapertures.

Each insulating member preferably comprises a planar base havingprojections standing away from the base to space the member from theadjacent first fixed contact element on one side, the base having anaperture aligned with each aperture of the adjacent first fixed contactelements and an insulating projection flanking a first side of eachaperture of one row and an insulating projection flanking the oppositeside of each aperture of the other row, the insulating members are firstfixed contact elements being so arranged that the aligned spaces betweenadjacent apertures of each row provide a socket for receiving a pin.each socket being flanked on each side by a contact of the first fixedcontact element, one insulated second fixed Contact element and oneun-insulated second fixed contact ele ment.

Preferably, on one side of each socket the insulated second fixedcontact element is nearer the socket entry than the un-insulated secondfixed contact element. whereas on the other side of the socket theinsulated second fixed contact element is further from the sockel entrythan the un-insulated second fixed contact element.

The pins suitably comprise an electrically insulated ciongate bodyhaving along one side face a first contact strip and along an oppositeside face a second Contact strip, the contact strips being so arrangedthat when the pin is inserted in a socket, the first contact stripengages a contact of the first fixed contact element on one side of thesocket, and the second contact strip engages the second fixed contacteiements on the opposite side 01 the socket, making electrical contactwith the uninsulated second fixed contact element.

At least one of the contact strips is suitably resilient and arranged toresist withdrawal of the pin from its socket, and at least one of thecontact strips is advantageously divided longitudinally to providedoublecontacts.

Each second fixed contact element suitably com prises an electricallyconductive rod, and each rod is advantageousiy split longitudinally withthe two halves insulated from one another, each half being associatedwith only one of the sockets fianking the second fixed contact element.

The first and second contact strips of each pin may be electricallyand/or mechanically connected together, but may otherwise be connectedtogether by an electrical component, preferably a diode. In this way thepin forms a diode pin which is advantageous in many applications of suchdevices.

A multi-socket assembly and a reversible contact pin therefor will nowbe more fully described by way of example and with reference to thedrawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective and partlyexploded view 01 part of the multi-socket assembly;

FIG. 2 is a front view of an insulating member ir contact with the firstfixed contact element;

FIG. 3 is a side view of an insulating member ir contact with a firstfixed contact element;

FIG. 4 is a side view of a reversible contact pin;

FIG, 5 is a view of two reversible contact pins in serted intorespective sockets one each direction.

DESCRIPTION OF THE PREFERRED EMBODIMENT A multi-socket assembly boardcomprises a first fixec contact elements I in the form of contactplates, sec ond fixed contact elements 2 in the form of contac rods andinsulating members 3. The plurality of firs contact elements 1 arearranged in a stack, with an insulating member 3 between adjacent firstcontact element 1.

Each insulating member 3, shown in FIG. 2, is made of insulatingplastics material, and has a series of aper tures 4 arranged in tworows, through which aperture: the contact rods 2 are inserted. A seriesof projection: 5 are provided, each projection 5 being associated witlan aperture 4. The apertures are arranged in two rows the top row 4abeing associated with the series of pro jections 5a, and the bottom row4b being associate: with the bottom row of projections Sb. Each of thepro jections 5a and 5b has a recess, the internal wall 0 which flankspart of the circumference of the corre sponding hole 4a or 5a. As shownin FIG. 2, the recesses of the projections 5a are situated to the leftof the corresponding holes 4a, and the recesses of the projections 5bare situated to the right of the corresponding apertures 4b.

The insulating member has a flange 6 (shown in FIG. 3) adapted to comeinto contact with the adjacent contact plate 1. The entire periphery ofthe opening of the sockets of the assembly is thus composed ofinsulating material, as shown in the rear part of FIG. 1. On the otherside of the insulating member 3 from the projections 5 there is providedan annular projecting flange 7 associated with each aperture 4.Apertures 8 of the contact plates 1 fit over the outside edges of theannular projecting flanges 7. The contact rods 2 pass through the holes9 of the insulating member 3 (shown in FIG. 3), and are thus insulatedfrom the contact plates 1.

Each contact plate 1 has a series of projections forming contact 10,each of which is adapted to fit into a corresponding well 11 in the bodyof the adjacent insulating member 3.

A reversible contact pin 12, shown in FIG. 4, comprises a base member13, l-i-shaped in cross-section and is made of an electricallyinsulative material, suitably a plastics material. A non-resilientcontact strip lies in a recess on one side of the base member 13 and hastwo outward protrusions 15 and 16 along the length of its body. Aresilient contact strip 17 is attached to the other side of the basemember 13 from the non-resilient contact strip and is mechanically andelectrically connected thereto, as shown at 14.

When in operation, as shown in H0. 5, a reversible contact pin isinserted into a socket, the resilient contact 17 comes into contact withthe associated first contact element and urges the non-resilient contactstrip towards the opposite wall of the socket. in the case of thecontact pin 12a, the non-resilient contact member strip is preventedfrom making contact with the rod 20 by reason of the intervening wall ofthe protrusion 5a, but the nonresilient contact member part 16 is urgedinto contact with rod 2b, thus making electrical connection betweencontact elements 10 and 2b.

In the case of the contact pin 12b, the non-resilient contact memberpart 16 is prevented from making contact with rod 2d, but part 15 isurged into contact with rod 26, thus making electrical connectionbetween contact elements 10 and 2c. Thus the current always flowsthrough the pin in the same direction.

it will be seen that each socket provides the possibil ity of electricalconnection between a first fixed contact element and either of twosecond fixed contact elements, depending on the direction of the pinwhen inserted.

The multi-socket assembly and associated programme pins just describedare susceptible to a number of modifications and adaptations.

The contact strips l5. l6 and 17 of the programme pins may belongitudinally split as shown in FIG. 4A to provide double-contacts.Such contacts are particularly advantageous in low current applications.

The heads of the programme pins shown in the drawing are in the form ofshort frusto-conical members, but for most applications, it will beconvenient to provide a cylindrical grip portion whose length is morenearly equal to that of the part of the pin bearing the contacts. Whilein the figures, the contact strips on the two sides of each pin havebeen shown mechanically connected together and thus electricallyshort-circuited together, in some applications, it may be convenient tosplit the two sets of contact strips, and possible to connect themtogether through an electrical component. A particular example of thisis the provision of a diode connecting together the two contact stripsto provide a diode pin which is advantageous in many applications ofsuch devices as shown in FIG. 4B.

The second contact element rods 2 may be longitudinally divided as shownin FIG. SA on a plane which is perpendicular to the plane of FIG. 5 andparallel to the axis of the programme pins. The two halves are insulatedfrom one another, and in this way each socket is provided with fourindependent contacts, each formed by one half of a contact rod. Theflexibility of an arrangement with the rods divided in this way isapparent.

In the figures, the contacts 10 of the first contact plates 1 are shownas cylindrical projections sweated into the plate. Another arrangementconsists in forming these contacts 10 integrally with the plate, forexample suitably shaped and arranged projections.

Although not shown in the figures, the front surface of the socketassembly may be covered with a facia provided with an aperture forreceiving each programme pin aligned with the sockets of the assembly.Such a facia can carry markings identifying the sockets for facilitatingthe setting up of a particular interconnection with the programme pins.

The hereinbefore described embodiment provides a multi-socket assemblyin which the contact elements have no moving parts, with the consequentadvantage that the possible break-down of spring contacts within theassembly is avoided.

An assembly as hereinbefore described can be made to different matrixdimensions, if required, e.g. 10 X 10 sockets, l8 X 32 sockets, etc., ormay include more than two layers of first and/or second contactelements, if this is desired.

1 claim:

1. A multi-socket assembly comprising a stack of laminar first fixedcontact elements, each having length and width dimensions significantlygreater than the thickness dimension and defining a plate with a majorplane lying within said length and width dimension and with the majorplanes of each first fixed contact element being disposed generallyparallel, one to another, insulating members interposed between adjacentstacked first fixed contact elements, a plurality of second fixedcontact elements each extending through the stack of first fixed contactelements and interposed insulating members and extending in a directionperpendicular to the major planes of said stack of first fixed contactelements, each insulating member between two adjacent first fixedcontact elements being adapted to insulate them from each other andbeing further adapted to insulate the first fixed contact elements fromthe second fixed contact elements, the insulating members each defininga plurality of sockets each adapted to receive a contact pin in one orother of two orientations to connect a first fixed contact element toone or other of two second fixed contact elements depending on theorientation of the inserted pin, said first fixed contact elements eachcomprising a plate with a row of contacts extending away from the platetowards the adjacent insulating member, and an aperture on either sideof each contact, said apertures forming two rows extending parallel tothe row of contacts, and said second fixed contact elements extendingthrough the aligned apertures,

2. An assembly according to claim 1, wherein the insulating members eachcomprise a planar base having projections standing away from the base tospace the member from the adjacent first fixed contact element on oneside, the base having an aperture aligned with each aperture of theadjacent first fixed contact elements, and an insulating projectionflanking a first side of each aperture of one row and an insulatingprojection flanking the opposite side of the aperture of the other row,the insulating members and first fixed contact elements being soarranged that the aligned spaces between adjacent apertures of each rowprovide the sockets for receiving the contact pins, each socket beingflanked on each side by a contact of the first fixed contact element,one insulated second fixed contact element, and one un-insulated secondfixed contact element.

3. An assembly according to claim 2 in combination with a contact pincomprising an electrically insulated elongate body having along one sideface a first contact strip and along an opposite side face a secondcontact strip, the contact strips being so arranged that when the pin isinserted in a socket the first contact strip engages a contact of thefirst fixed contact element on one side only of the socket and thesecond contact strip engages the second fixed contact elements on theopposite side of the socket, making electrical contact with theuninsulated second fixed contact element.

4. The combination according to claim 3, wherein at least one of thecontact strips is resilient and arranged to resist withdrawal of the pinwhen inserted in a socket.

5. The combination according to claim 3, wherein the first and secondcontact strips are short-circuited together.

6. The combination according to claim 3, wherein the first and secondcontact strips are electrically connected together through an electricalcomponent housed in a grip portion of the pin.

7. The combination according to claim 6, wherein the component is adiode.

8. A multi-socket assembly comprising a stack of laminar first fixedcontact elements, each having length and width dimensions significantlygreater than the thickness dimension and defining a plate with a majorplane lying within said length and width dimension and with the majorplanes of each first fixed contact element being disposed generallyparallel, one to another, insulating members interposed between adjacentstacked first fixed contact elements, a plurality of second fixedcontact elements each extending through the stack of first fixed contactelements and interposed insulating members and extending in a directionperpendicular to the major planes of said stack of first fixed contactelements, each insulating member between two adjacent first fixedcontact elements being adapted to insulate them from each other andbeing further adapted to insulate the first fixed contact elements fromthe second fixed contact elements, the insulating members each defininga plurality of sockets each adapted to receive a contact pin in one orother of two orientations to connect a first fixed contact element toone or other of two second fixed contact elements depending on theorientation of the inserted pin, each second fixed contact elementcomprising an electrically conductive rod which is longitudinally splitwith the two halves insulated from one another, each half beingassociated with one only of the sockets flanking the rod.

9. A multi-socket assembly comprising a stack of laminar first fixedcontact elements. each having length and width dimensions significantlygreater than the thickness dimension and defining a plate with a majorplane lying within said length and width dimension and with the majorplanes of each first fixed contact element being disposed generallyparallel, one to another, insulating members between adjacent stackedfirst fixed contact elements, a plurality of second fixed contactelements each extending through the stack of first fixed contactelements and interposed insulating members and extending in a directionperpendicular to the major planes of said stack of first fixed contactelements, wherein the first fixed contact elements each comprise a platewith a row of contacts extending away from the plate towards theadjacent insulating member, and an aperture on either side of eachcontact, these apertures forming two rows extending parallel to the rowof contacts, the second fixed contact elements extending through thealigned apertures, and wherein the insulating members each comprise aplanar base having projections standing away from the base to space themember from the adjacent first fixed contact element on one-side, thebase having an aperture aligned with each aperture of the adjacent firstfixed contact elements, and an insulating projection flanking a firstside of each aperture of one row and an insulating projection flankingthe opposite side of the aperture of the other row, the insulatingmembers and first fixed contact elements being so arranged that thealigned spaces between adjacent apertures of each row provide thesockets for receiving the contact pins, each socket being flanked oneach side by a contact of the first fixed contact element, one insulatedsecond fixed contact element, and one un-insulated second fixed contactelement, wherein on one side of each socket the insulated second fixedcontact element is nearer the socket entry than the un-insulated secondfixed contact element, while on the other side of the socket, theinsulated second fixed contact element is further from the socket entrythan the un-insulated second fixed contact element.

10. A multi-socket assembly comprising a stack of laminar first fixedcontact elements, each having length and width dimensions significantlygreater than the thickness dimension and defining a plate with a majorplane lying within said length and width dimension and with the majorplanes of each first fixed contact element being disposed generallyparallel, one to another, insulating members between adjacent stackedfirst fixed contact elements, a plurality of second fixed contactelements each extending through the stack of first fixed contactelements and interposed insulating members and extending in a directionperpendicular to the major planes of said stack of first fixed contactelements, each insulating member between two adjacent first fixedcontact elements being adapted to insulate them from each other andbeing further adapted to insulate the first fixed contact elements fromthe second fixed contact elements, the insulating members each defininga plurality of sockets each adapted to receive a contact pin in one orother of two orientations to connect a first fixed contact element toone or other of two second fixed contact elements depending on theorientation of the inserted pin, in which each second fixed contactelement comprises an electrically conductive rod which is longitudinallysplit with the two halves insulated from one another, each half beingassociated with one only of the sockets flanking the rod, wherein eachrod is split on a plane parallel to the socket axes.

11. In combination:

a. a multi-socket assembly comprising a stack of laminar first fixedcontact elements, each having length and width dimensions significantlygreater than the thickness dimension and defining a plate with a majorplane lying within said length and width dimension and with the majorplanes of each first fixed contact element being disposed generallyparallel, one to another, insulating members between adjacent stackedfirst fixed contact elements, a plurality of second fixed contactelements each extending through the stack of first fixed contactelements and interposed insulating members and extending in a directionperpendicular to the major planes of said stack of first fixed contactelements each insulating member between two adjacent first fixed contactelements being adapted to insulate them from each other and beingfurther adapted to insulate the first fixed contact elements from thesecond fixed contact elements, the insu lating members each defining aplurality of sockets each adapted to receive a contact pin in one or theother of two orientations to connect a first fixed contact element toone or the other of two second fixed contact elements depending on theorientation of the inserted pin, wherein the first fixed contactelements each comprise a plate with a row of contacts extending awayfrom the plate towards the adjacent insulating member, and an apertureon either side of each contact, these apertures forming two rowsextending parallel to the row of contacts, the second fixed contactelements extending through the aligned apertures, and wherein theinsulating members each comprise a planar base having projectionsstanding away from the base to space the member from the adjacent firstfixed contact element on one side, the base having an aperture alignedwith each aperture of the adjacent first fixed contact elements, and aninsulating projection flanking a first side of each aperture of one rowand an insulating projection flanking the opposite side of the apertureof the other row, the insulating members and first fixed contactelements being so arranged that the aligned spaces between adjacentapertures of each row provide the sockets for receiving the contactpins, each socket being flanked on each side by a contact of the firstfixed contact element, one insulated second fixed contact element, andone un-insulated second fixed contact element; and

b. a contact pin comprising an electrically insulated elongated bodyhaving along one side face a first contact strip and along an oppositeside face a second contact strip, the contact strips being so arrangedthat when the pin is inserted in a socket the first contact stripengages a contact of the first fixed contact element one side only ofthe socket and the second contact strip engages the second fixed contactelements on the opposite side of the socket, making electrical contactwith the uninsulated second contact element, wherein at least one of thecontact strips is longitudinally divided to provide double contacts.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO.3,904,263 DATED September 9 1975 INVENTOR(S) John Philip Norman H iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown betow- Item 76, "JohnPhillip Norman" should read John Philip Norman Column 8, line 33,sub-paragraph (b) of Claim 11, after "second" insert fixed Signed andScaled this tenth Day Of February 1976 [SEAL] Arrest.-

RUTH C. MASON C. MARSHALL DANN Arresting Officer (ummissinner nj'Parentsand Trademarks

1. A multi-socket assembly comprising a stack of laminar first fixedcontact elements, each having length and width dimensions significantlygreater than the thickness dimension and defining a plate with a majorplane lying within said length and width dimension and with the majorplanes of each first fixed contact element being disposed generallyparallel, one to another, insulating members interposed between adjacentstacked first fixed contact elements, a plurality of second fixedcontact elements each extending through the stack of first fixed contactelements and interposed insulating members and extending in a directionperpendicular to the major planes of said stack of first fixed contactelements, each insulating member between two adjacent first fixedcontact elements being adapted to insulate them from each other andbeing further adapted to insulate the first fixed contact elements fromthe second fixed contact elements, the insulating members each defininga plurality of sockets each adapted to receive a contact pin in one orother of two orientations to connect a first fixed contact element toone or other of two second fixed contact elements depending on theorientation of the inserted pin, said first fixed contact elements eachcomprising a plate with a row of contacts extending away from the platetowards the adjacent insulating member, and an aperture on either sideof each contact, said apertures forming two rows extending parallel tothe row of contacts, and said second fixed contact elements extendingthrough the aligned apertures.
 2. An assembly according to claim 1,wherein the insulating members each comprise a planar base havingprojections standing away from the base to space the member from theadjacent firSt fixed contact element on one side, the base having anaperture aligned with each aperture of the adjacent first fixed contactelements, and an insulating projection flanking a first side of eachaperture of one row and an insulating projection flanking the oppositeside of the aperture of the other row, the insulating members and firstfixed contact elements being so arranged that the aligned spaces betweenadjacent apertures of each row provide the sockets for receiving thecontact pins, each socket being flanked on each side by a contact of thefirst fixed contact element, one insulated second fixed contact element,and one un-insulated second fixed contact element.
 3. An assemblyaccording to claim 2 in combination with a contact pin comprising anelectrically insulated elongate body having along one side face a firstcontact strip and along an opposite side face a second contact strip,the contact strips being so arranged that when the pin is inserted in asocket the first contact strip engages a contact of the first fixedcontact element on one side only of the socket and the second contactstrip engages the second fixed contact elements on the opposite side ofthe socket, making electrical contact with the un-insulated second fixedcontact element.
 4. The combination according to claim 3, wherein atleast one of the contact strips is resilient and arranged to resistwithdrawal of the pin when inserted in a socket.
 5. The combinationaccording to claim 3, wherein the first and second contact strips areshort-circuited together.
 6. The combination according to claim 3,wherein the first and second contact strips are electrically connectedtogether through an electrical component housed in a grip portion of thepin.
 7. The combination according to claim 6, wherein the component is adiode.
 8. A multi-socket assembly comprising a stack of laminar firstfixed contact elements, each having length and width dimensionssignificantly greater than the thickness dimension and defining a platewith a major plane lying within said length and width dimension and withthe major planes of each first fixed contact element being disposedgenerally parallel, one to another, insulating members interposedbetween adjacent stacked first fixed contact elements, a plurality ofsecond fixed contact elements each extending through the stack of firstfixed contact elements and interposed insulating members and extendingin a direction perpendicular to the major planes of said stack of firstfixed contact elements, each insulating member between two adjacentfirst fixed contact elements being adapted to insulate them from eachother and being further adapted to insulate the first fixed contactelements from the second fixed contact elements, the insulating memberseach defining a plurality of sockets each adapted to receive a contactpin in one or other of two orientations to connect a first fixed contactelement to one or other of two second fixed contact elements dependingon the orientation of the inserted pin, each second fixed contactelement comprising an electrically conductive rod which islongitudinally split with the two halves insulated from one another,each half being associated with one only of the sockets flanking therod.
 9. A multi-socket assembly comprising a stack of laminar firstfixed contact elements, each having length and width dimensionssignificantly greater than the thickness dimension and defining a platewith a major plane lying within said length and width dimension and withthe major planes of each first fixed contact element being disposedgenerally parallel, one to another, insulating members between adjacentstacked first fixed contact elements, a plurality of second fixedcontact elements each extending through the stack of first fixed contactelements and interposed insulating members and extending in a directionperpendicular to the major planes of said stack of first fixed contactelements, wherein the first fixed contact elemenTs each comprise a platewith a row of contacts extending away from the plate towards theadjacent insulating member, and an aperture on either side of eachcontact, these apertures forming two rows extending parallel to the rowof contacts, the second fixed contact elements extending through thealigned apertures, and wherein the insulating members each comprise aplanar base having projections standing away from the base to space themember from the adjacent first fixed contact element on one side, thebase having an aperture aligned with each aperture of the adjacent firstfixed contact elements, and an insulating projection flanking a firstside of each aperture of one row and an insulating projection flankingthe opposite side of the aperture of the other row, the insulatingmembers and first fixed contact elements being so arranged that thealigned spaces between adjacent apertures of each row provide thesockets for receiving the contact pins, each socket being flanked oneach side by a contact of the first fixed contact element, one insulatedsecond fixed contact element, and one un-insulated second fixed contactelement, wherein on one side of each socket the insulated second fixedcontact element is nearer the socket entry than the un-insulated secondfixed contact element, while on the other side of the socket, theinsulated second fixed contact element is further from the socket entrythan the un-insulated second fixed contact element.
 10. A multi-socketassembly comprising a stack of laminar first fixed contact elements,each having length and width dimensions significantly greater than thethickness dimension and defining a plate with a major plane lying withinsaid length and width dimension and with the major planes of each firstfixed contact element being disposed generally parallel, one to another,insulating members between adjacent stacked first fixed contactelements, a plurality of second fixed contact elements each extendingthrough the stack of first fixed contact elements and interposedinsulating members and extending in a direction perpendicular to themajor planes of said stack of first fixed contact elements, eachinsulating member between two adjacent first fixed contact elementsbeing adapted to insulate them from each other and being further adaptedto insulate the first fixed contact elements from the second fixedcontact elements, the insulating members each defining a plurality ofsockets each adapted to receive a contact pin in one or other of twoorientations to connect a first fixed contact element to one or other oftwo second fixed contact elements depending on the orientation of theinserted pin, in which each second fixed contact element comprises anelectrically conductive rod which is longitudinally split with the twohalves insulated from one another, each half being associated with oneonly of the sockets flanking the rod, wherein each rod is split on aplane parallel to the socket axes.
 11. In combination: a. a multi-socketassembly comprising a stack of laminar first fixed contact elements,each having length and width dimensions significantly greater than thethickness dimension and defining a plate with a major plane lying withinsaid length and width dimension and with the major planes of each firstfixed contact element being disposed generally parallel, one to another,insulating members between adjacent stacked first fixed contactelements, a plurality of second fixed contact elements each extendingthrough the stack of first fixed contact elements and interposedinsulating members and extending in a direction perpendicular to themajor planes of said stack of first fixed contact elements, eachinsulating member between two adjacent first fixed contact elementsbeing adapted to insulate them from each other and being further adaptedto insulate the first fixed contact elements from the second fixedcontact elements, the insulating members each defining a plurality ofsockets each adapted to receive a contact pIn in one or the other of twoorientations to connect a first fixed contact element to one or theother of two second fixed contact elements depending on the orientationof the inserted pin, wherein the first fixed contact elements eachcomprise a plate with a row of contacts extending away from the platetowards the adjacent insulating member, and an aperture on either sideof each contact, these apertures forming two rows extending parallel tothe row of contacts, the second fixed contact elements extending throughthe aligned apertures, and wherein the insulating members each comprisea planar base having projections standing away from the base to spacethe member from the adjacent first fixed contact element on one side,the base having an aperture aligned with each aperture of the adjacentfirst fixed contact elements, and an insulating projection flanking afirst side of each aperture of one row and an insulating projectionflanking the opposite side of the aperture of the other row, theinsulating members and first fixed contact elements being so arrangedthat the aligned spaces between adjacent apertures of each row providethe sockets for receiving the contact pins, each socket being flanked oneach side by a contact of the first fixed contact element, one insulatedsecond fixed contact element, and one un-insulated second fixed contactelement; and b. a contact pin comprising an electrically insulatedelongated body having along one side face a first contact strip andalong an opposite side face a second contact strip, the contact stripsbeing so arranged that when the pin is inserted in a socket the firstcontact strip engages a contact of the first fixed contact element oneside only of the socket and the second contact strip engages the secondfixed contact elements on the opposite side of the socket, makingelectrical contact with the un-insulated second contact element, whereinat least one of the contact strips is longitudinally divided to providedouble contacts.